/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.transforms;



import com.bff.gaia.unified.model.pipeline.v1.RunnerApi;

import com.bff.gaia.unified.model.pipeline.v1.RunnerApi.StandardSideInputTypes;

import com.bff.gaia.unified.sdk.annotations.Experimental;

import com.bff.gaia.unified.sdk.annotations.Experimental.Kind;

import com.bff.gaia.unified.sdk.annotations.Internal;



import javax.annotation.Nullable;



/**

 * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

 *

 * <p>Utility methods for constructing known {@link Materialization materializations} for a {@link

 * ViewFn}.

 */

@Internal

public class Materializations {

  /**

   * The URN for a {@link Materialization} where the primitive view type is an iterable of fully

   * specified windowed values.

   */

  @Experimental(Kind.CORE_RUNNERS_ONLY)

  public static final String ITERABLE_MATERIALIZATION_URN =

      StandardSideInputTypes.Enum.ITERABLE

          .getValueDescriptor()

          .getOptions()

          .getExtension(RunnerApi.unifiedUrn);



  /**

   * The URN for a {@link Materialization} where the primitive view type is a multimap of fully

   * specified windowed values.

   */

  @Experimental(Kind.CORE_RUNNERS_ONLY)

  public static final String MULTIMAP_MATERIALIZATION_URN =

      StandardSideInputTypes.Enum.MULTIMAP

          .getValueDescriptor()

          .getOptions()

          .getExtension(RunnerApi.unifiedUrn);



  /**

   * Represents the {@code PrimitiveViewT} supplied to the {@link ViewFn} when it declares to use

   * the {@link Materializations#ITERABLE_MATERIALIZATION_URN iterable materialization}.

   *

   * @param <V>

   */

  public interface IterableView<V> {

    Iterable<V> get();

  }



  /**

   * Represents the {@code PrimitiveViewT} supplied to the {@link ViewFn} when it declares to use

   * the {@link Materializations#MULTIMAP_MATERIALIZATION_URN multimap materialization}.

   */

  public interface MultimapView<K, V> {

    Iterable<V> get(@Nullable K k);

  }



  /**

   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

   *

   * <p>A {@link Materialization} where the primitive view type is a multimap with fully specified

   * windowed values.

   */

  @Internal

  public static <K, V> Materialization<MultimapView<K, V>> multimap() {

    return new Materialization<MultimapView<K, V>>() {

      @Override

      public String getUrn() {

        return MULTIMAP_MATERIALIZATION_URN;

      }

    };

  }



  /**

   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>

   *

   * <p>A {@link Materialization} where the primitive view type is an iterable with fully specifed

   * windowed values.

   */

  @Internal

  public static <V> Materialization<IterableView<V>> iterable() {

    return new Materialization<IterableView<V>>() {

      @Override

      public String getUrn() {

        return ITERABLE_MATERIALIZATION_URN;

      }

    };

  }

}